Dallas Peterson, professor and weed management specialist for K-State Research and Extension, is a co-author for the publication. He said much has changed in the magnitude of the weed control guide, but the purpose remains the same.

“(In 1967) it consisted of 12 pages, with large print and a lot of white space,” Peterson said. “The current guide is about 135 pages with very condensed print and contains much more herbicide information. It has always been intended to be a resource to help farmers and crop advisors with selecting herbicides and using them appropriately.”

The 1967 edition listed 16 herbicide active ingredients, Peterson said, while the latest edition includes 93 active ingredients. In addition to those 93, the guide also includes generic products and pre-mix combinations. This is why herbicide selection today can be overwhelming.

“Probably the first place you would go to for reference would be the efficacy tables,” Peterson said. “They have the various herbicide treatments and combinations listed by application timing, whether that is a pre-plant, pre-emergence or post-emergence herbicide. Then it provides ratings for the kind of weed control we would anticipate on the common weed species in those crops.”

Popular Kansas crops, including specialty crops, and the herbicide options available for those crops are listed individually. K-State experts base the information included in the guide on field trial evaluations, evaluations of new and established herbicides for crop tolerance and weed control, and recommendations from chemical professionals and other agronomists who have performed herbicide testing in other states.

Along with the efficacy tables is information about safe use and handling, protective equipment and herbicide resistance management. There is also a cost table available, which Peterson said was developed by soliciting information from distributors and adding in a percentage markup for retail. It does not account for discounts that might be available through local retailers, so growers might end up paying less than the amount projected.

Additionally, there is information about managing pastures and rangeland, land enrolled in the Conservation Reserve Program, noncropland and noxious weeds as well.

Peterson said the guide is just one source for weed control. People should also consult their local crop advisors on herbicide application, as products might perform differently in certain parts of Kansas. It is also not meant to serve as a replacement to the herbicide label, which is important for people to read.

“The herbicide label is the law, and that’s the resource you should go to when using those herbicides,” Peterson said. “But, this guide does provide some comparisons, restrictions and how the various herbicides should be utilized.”

It is surprising how many changes have to be made to the guide annually, Peterson said. Therefore, he recommends for anyone who has an outdated copy to get the 2014 edition. Log on to the K-State Research and Extension Bookstore for a digital copy of Chemical Weed Control for Field Crops, Pastures, Rangeland, and Noncropland, or ask for a printed copy at your local extension office.

K-State Research and Extension is a short name for the Kansas State University Agricultural Experiment Station and Cooperative Extension Service, a program designed to generate and distribute useful knowledge for the well-being of Kansans. Supported by county, state, federal and private funds, the program has county Extension offices, experiment fields, area Extension offices and regional research centers statewide. Its headquarters is on the K-State campus, Manhattan.